Display Devices

Abstract

A display device according to an exemplary embodiment includes a display panel including a display area and a bending area. The display panel in the bending area includes a plurality of connection wires, a pattern including a plurality of electrodes, and a protective layer between the plurality of connection wires and the pattern.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0028278 filed in the Korean Intellectual Property Office on March 9, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a display device. Background Art

[0004] Display devices such as organic light emitting diode displays, liquid crystal displays, etc. are manufactured by forming several layers or elements on a substrate. Glass is used as a substrate for display devices. However, the substrate is heavy and easily damaged when made of glass. In addition, because the glass substrate is rigid, it is difficult to modify the display device. Recently, display devices using flexible substrates that are light, impact-resistant, and easy to modify have been developed.

[0005] A display device using a flexible substrate may be designed to bend an edge of a display panel including a pad portion to face the back of the screen, wherein a flexible printed circuit film (FPC) for transmitting a signal is attached to the pad portion. Therefore, compared with a display device using a rigid substrate, dead space may be reduced. If the dead space is reduced, the frame width of the display device may be reduced and the utilization rate of the internal space of the display device may be improved, thereby designing the display device to be more compact.

[0006] The above information disclosed in this Background section is only for enhancement of understanding of the background and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Summary of the invention

[0007] Example embodiments provide a display device capable of improving physical characteristics of a curved region of a display panel and easily and correctly evaluating processing characteristics of the curved region.

[0008] A display device according to an exemplary embodiment includes a display panel including a display area and a bending area. The display panel in the bending area may include a plurality of connection wires, a pattern including a plurality of electrodes, and a protective layer between the plurality of connection wires and the pattern.

[0009] The plurality of electrodes may be arranged over at least about 50% of the curved area.

[0010] Each electrode may be quadrilateral or circular.

[0011] The pattern may also include a plurality of bridges connecting the plurality of electrodes.

[0012] The display panel may further include a substrate, and the plurality of connection wires may be positioned across the bending region on the substrate and may be configured to transmit signals from the display panel.

[0013] The protection layer may be located on the plurality of connecting wires, and the pattern is located on the protection layer.

[0014] The display panel may further include a pixel electrode located in the display area, and the pattern may be made of the same material as the pixel electrode.

[0015] The protection layer may be located between the substrate and the plurality of connection wires, and the pattern may be located between the substrate and the protection layer.

[0016] The display panel may further include a gate electrode in the display area, and the pattern may be made of the same material as the gate electrode.

[0017] The display panel may further include a first alignment mark and a second alignment mark respectively located at both sides in the bending region, and the pattern may be located between the first alignment mark and the second alignment mark.

[0018] The pattern may also include a plurality of dummy electrodes adjacent to the curved region.

[0019] A display device according to an exemplary embodiment includes: a display panel including a display area and a bending area, and a protective film positioned on one surface of the display panel so as not to overlap with the bending area. The display panel includes a pattern including a plurality of electrodes arranged in the bending area, the protective film includes a first portion and a second portion respectively located at both sides of the bending area, and a portion of the pattern overlaps at least one of the first portion and the second portion.

[0020] The pattern may include a plurality of sub-patterns, and each sub-pattern may include a plurality of electrodes symmetrically positioned with respect to one edge of the bending region.

[0021] Each of the sub-patterns may include a plurality of electrodes, the number of which changes as being farther from the edge of the bending region.

[0022] Each of the sub-patterns may include a plurality of electrodes, the number of the plurality of electrodes increasing as being farther away from an edge of the bending region.

[0023] Each electrode may be quadrilateral or circular.

[0024] Each sub-pattern may include a plurality of electrodes having two or more shapes.

[0025] The display panel may further include a substrate and a plurality of connection wires crossing the bending region on the substrate, and the pattern may be located at the same layer as the plurality of connection wires.

[0026] In the bending area, the display panel may further include a first protective layer between the substrate and the plurality of connection wires and a second protective layer on the plurality of connection wires, and the pattern may be between the first protective layer and the second protective layer.

[0027] The display panel may further include a source electrode and a drain electrode located in the display area, and the pattern may be made of the same material as the source electrode and the drain electrode.

[0028] According to the exemplary embodiment, the adhesive remaining in the curved area of ​​the display panel can be easily evaluated quantitatively, and the bending stress of the curved area can be relieved. The cutting accuracy of the protective film removed from the curved area of ​​the display panel can be easily and accurately evaluated, and the measurement and evaluation can be automated through visual inspection, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a top plan view schematically illustrating a display device according to an exemplary embodiment.

[0030] Figure 2 yes Figure 1 A side view of the display device shown in FIG. 1 before being bent.

[0031] Figure 3 yes Figure 1 A side view of the display device shown in FIG. 5 after being bent.

[0032] Figure 4 yes Figure 1 Magnified view of the curved area in .

[0033] Figure 5 It is along Figure 1 A cross-sectional view taken along line V-V'.

[0034] Figure 6 It is schematically shown Figure 1 View of the cross-sectional structure in the bending region.

[0035] Figure 7 yes Figure 1 Magnified view of the bending region in FIG. 1 and the area adjacent to the bending region.

[0036] Figure 8 and Fig. 9 is a view illustrating a pattern located at a bending region of a display device according to an exemplary embodiment.

[0037] Fig.10 and Fig.11 : is a graph showing the influence on the connection conductive line when the bending area is bent according to the shape of the pattern.

[0038] Fig.12is a graph showing the influence on the connecting wire when the bending region is bent according to the curvature radius.

[0039] Fig.13 is a side view of the display apparatus according to the exemplary embodiment after being bent.

[0040] Fig.14 is a cross-sectional view of a display device according to an exemplary embodiment.

[0041] Fig.15 is a top plan view schematically illustrating a display device according to an exemplary embodiment.

[0042] Fig.16 It is along Fig.15 A cross-sectional view taken along line XVI-XVI'.

[0043] Fig.17 , Fig.18 , Fig.19 and Fig. 20 According to an exemplary embodiment, Fig.15 Magnified view of the area indicated by the single-dot dash line. DETAILED DESCRIPTION

[0044] The inventive concept will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. As those skilled in the art will realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the inventive concept.

[0045] Throughout the specification, the same reference numerals refer to the same elements. In the drawings, in order to clearly show the arrangement and relative positions of corresponding layers and corresponding regions, the thickness or size of corresponding layers and corresponding regions may be exaggerated or reduced.

[0046] It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements.

[0047] In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0048] Furthermore, in the specification, the wording “in a plan view” means when an object portion is viewed from above, and the wording “in a cross-sectional view” means when a cross section obtained by vertically cutting the object portion is viewed from the side.

[0049] Now, a display device according to an exemplary embodiment will be described with reference to the accompanying drawings. Although an organic light emitting diode display is described as a display device, the inventive concept is not limited thereto and the inventive concept may be applied to other display devices such as a liquid crystal display.

[0050] Figure 1 is a top plan view schematically illustrating a display device according to an exemplary embodiment. Figure 2 yes Figure 1 A side view of the display device shown in FIG. 1 before being bent. Figure 3 yes Figure 1 A side view of the display device shown in FIG. 5 after being bent.

[0051] refer to Figure 1 , the display device includes a display panel 10, a flexible printed circuit film 20 attached to the display panel 10, a driving device including an integrated circuit chip 30, and the like.

[0052] The display panel 10 includes a display area DA corresponding to a screen displaying an image and a non-display area NA in which circuits and / or signal lines for generating and / or transmitting various signals applied to the display area DA are arranged around the display area DA. Figure 1 , the inside and the outside of the dotted quadrilateral correspond to the display area DA and the non-display area NA, respectively.

[0053] The pixels PX are arranged in a matrix form, for example, in a display area DA of the display panel 10. Signal lines (not shown), such as scan lines (referred to as gate lines), light emission control lines, data lines, and drive voltage lines, are also arranged in the display area DA. The scan lines, light emission control lines, data lines, and drive voltage lines are connected to each pixel PX, and each pixel PX can receive scan signals (referred to as gate signals), light emission control signals, data signals, and drive voltages from these signal lines.

[0054] The display area DA may include a touch sensor layer for sensing a contact touch or a non-contact touch of a user. Although the display area DA is shown as having a quadrilateral shape with rounded corners, the display area DA may have various shapes such as a polygonal shape, a circular shape, an elliptical shape, etc.

[0055] A pad portion PP in which a pad for receiving a signal from outside the display panel 10 is disposed is positioned in the non-display area NA of the display panel 10. The pad portion PP may be positioned to extend in the first direction x along one edge of the display panel 10. The flexible printed circuit film 20 may be bonded to the pad portion PP, and a pad of the flexible printed circuit film 20 may be electrically connected to a pad of the pad portion PP.

[0056] A driving device (not shown) that generates and / or processes various signals for driving the display panel 10 may also be located in the non-display area NA. The driving device may include a data driver that applies a data signal to a data line, a scan driver that applies a scan signal to a scan line, a light emission driver that applies a light emission control signal to a light emission control line, and a signal controller that controls the data driver, the scan driver, and the light emission driver. The scan driver and the light emission driver may be integrated on the display panel 10. The data driver and the signal controller may be provided as an integrated circuit chip (referred to as a driver IC chip) 30, and the integrated circuit chip 30 may be mounted in the non-display area NA of the display panel 10. The integrated circuit chip 30 may be mounted to a flexible printed circuit board (PCB) that may be electrically connected to the display panel 10.

[0057] refer to Figure 1 , Figure 2 and Figure 3 , the display panel 10 includes a bending region BR. For example, the bending region BR may be located at the non-display region NA between the display region DA and the pad portion PP. The bending region BR may be located to cross the display panel 10 in the first direction x. Figure 3 As shown in , the display panel 10 may be bent with a predetermined curvature radius in the bending area BR based on a bending axis parallel to the first direction x. When the display panel 10 is a top emission type, the display panel 10 may be bent so that the pad portion PP and the flexible printed circuit film 20 are farther from the display area DA than the bending area BR located at the back of the display panel 10. In an electronic device to which the display device is applied, the display panel 10 may be in a bent state as described above.

[0058] The bending region BR may be bent around one bending axis, however, the bending region BR may be bent around two or more bending axes. In the figure, the bending region BR is located at the non-display region NA, however, the bending region BR may be located above the display region DA and the non-display region NA, or may be located in the display region DA.

[0059] refer to Figure 2 and Figure 3 , a protective film 50 for protecting the display panel 10 is located under the display panel 10. The protective film 50 is attached to the rear surface of the display panel 10 by an adhesive. The protective film 50 may be made of plastic such as polyethylene terephthalate, polyethylene naphthalate, polyimide, polyethylene sulfide, and the like.

[0060] The protective film 50 is positioned to cover the entire rear surface of the display panel 10, but it is not located in the bending region BR to reduce the bending stress of the bending region BR. The protective film 50 can be formed by adhering the protective film to the entire rear surface of the display panel 10 and then removing the protective film portion located in the bending region BR.

[0061] In more detail, a protective film in which an adhesive (such as a pressure-sensitive adhesive) is applied to one surface is uniformly adhered to the entire rear surface of the display panel 10 by a roll lamination method. Next, the adhesive provided in the curved region BR is photodecomposed by irradiating ultraviolet rays to the curved region BR so that the adhesive force is degraded, and the protective film is cut along the first direction x at both sides of the curved region BR (both sides in the second direction y). Next, the protective film portion whose both sides are cut located in the curved region BR is peeled off. When cutting the protective film, a Figure 4 The alignment marks AM shown in FIG. 1 are used to align a cutting device such as a laser cutter.

[0062] The adhesive disposed in the bending region BR may be removed together with the removed protective film portion, however a portion of the adhesive may remain at the rear surface of the display panel 10 in the bending region BR. Particles are attached to the remaining adhesive (hereinafter referred to as residual adhesive) so that the display panel 10 may be contaminated and defects may occur. According to an exemplary embodiment, the display panel 10 includes a pattern IP capable of measuring the residual adhesive, and this refers to Figure 4 and Figure 5 Detailed description.

[0063] Figure 4 yes Figure 1 A magnified view of the curved region in Figure 5 It is along Figure 1 A cross-sectional view taken along line V-V'.

[0064] Figure 4 The pattern IP located in the bending region BR and the residual adhesive R located in the bending region BR are shown. Figure 5 As shown in FIG. 1 , a plurality of connecting wires 179 crossing the bending region BR in the second direction y are located in the bending region BR, and in order to avoid the complexity of the figure, Figure 4 Only the pattern IP and the alignment mark AM are shown.

[0065] refer to Figure 4, the display panel 10 includes a pattern IP, and the pattern IP includes a plurality of electrodes E in the curved region BR. The electrode E having a quadrilateral shape is shown, but the electrode E may have various shapes other than the quadrilateral, such as a polygon, a circle, or an ellipse. In the curved region BR, the number of electrodes E may be about 20 to about 2000, about 50 to about 1000, or about 100 to about 500. The electrode E configured with the pattern IP may be located above about 50%, about 70%, or about 90% of the curved region BR, or may be uniformly located above substantially the entire curved region BR. The electrodes E may have the same shape and may be arranged at the same intervals. The electrode E may be a square whose length l of one side is about 20 μm to about 100 μm, and the pitch p of the electrode E may be about 30 μm to about 150 μm. For example, when the pitch p of the electrodes E is set to about 70 μm, the electrodes E having a length l of about 50 μm may be arranged at an interval s of about 20 μm, and the electrodes E having a length l of about 35 μm may be arranged at an interval s of about 35 μm. In the bending region BR, the pattern IP may be formed to have an area density of about 10% to about 80%, an area density of about 20% to about 70%, or an area density of about 30% to about 60%.

[0066] If the pattern IP is formed in the bent region BR, the extent of the residual adhesive R can be confirmed very simply and quantitatively by simply observing the number of electrodes E overlapping with the residual adhesive R or not overlapping with the residual adhesive R through visual inspection. Figure 4 , the pattern IP includes 120 electrodes E. If the electrodes E of which 50% or more of the area overlaps with the residual adhesive R are set as overlapped electrodes E, there are about 50 such overlapped electrodes E. In other words, it can be confirmed that the area density of the residual adhesive R is about 42% (equal to 50 / 120×100%) of the bending region BR. Because the brightness may be different when the electrodes E overlapped with the residual adhesive R and those not overlapped with the residual adhesive R are checked using an optical microscope, complex equipment or algorithms are not required to confirm the overlap.

[0067] If the residual adhesive R does not overlap above a predetermined level, a subsequent process for manufacturing a display device may be performed or the display device may be shipped, and if the overlap of the residual adhesive R is above a predetermined level, the display device may be considered defective. Because the pattern IP is uniformly arranged over the entire bending region BR, the pattern IP also has a function of relieving bending stress of the bending region BR and controlling a neutral plane, along with a function of evaluating the residual adhesive R. A detailed description thereof will be given later, and first reference is made to Figure 5 How the pattern IP is formed in the display panel 10 is described.

[0068] The alignment mark AM may be located at both sides in the first direction x in the bending region BR. Therefore, the pattern IP may be located between the alignment marks AM in the bending region BR. The alignment mark AM may have a cross planar shape as shown or may have other shapes.

[0069] refer to Figure 5 , schematically showing a cross-sectional view of a display area DA and a bending area BR of a display panel 10. The display panel 10 includes a substrate 110 and a plurality of layers, wires, and components formed on the substrate 110. In the display area DA of the display panel 10, a very large number of pixels are provided, but only one pixel is shown and described to avoid graphic complexity. In addition, each pixel includes a transistor, a capacitor, and an organic light emitting diode, however, the stacked structure of the display panel 10 is described based on one transistor TR and one organic light emitting diode OLED connected to the transistor TR.

[0070] The substrate 110 may be a flexible substrate. The substrate 110 may be made of a polymer such as polyimide, polyamide, polycarbonate, and polyethylene terephthalate. The substrate 110 may include a barrier layer for preventing moisture and the like from penetrating from the outside. The barrier layer may include an inorganic insulating material such as silicon oxide (SiO x ), silicon nitride (SiN x )wait.

[0071] The buffer layer 120 is located on the substrate 110. The buffer layer 120 plays a role in preventing impurities that may diffuse from the substrate 110 to the semiconductor layer 154 in the process of forming the semiconductor layer 154 and reducing the stress applied to the substrate 110. The buffer layer 120 may include an inorganic insulating material such as silicon oxide, silicon nitride, etc. The buffer layer 120 may be located over the entire surface of the substrate 110, however, the buffer layer 120 may not be located in the bending region BR. This is because a layer formed of an inorganic insulating material is easily damaged by bending, so that cracks may occur or the wire located in the bending region BR may be damaged.

[0072] The semiconductor layer 154 of the transistor TR is located on the buffer layer 120. The semiconductor layer 154 includes a channel region overlapping the gate electrode 124 and a source region and a drain region disposed at respective sides of the channel region. The semiconductor layer 154 may include polysilicon, amorphous silicon, or an oxide semiconductor.

[0073] The first insulating layer 140 including an inorganic insulating material such as silicon oxide or silicon nitride is located on the semiconductor layer 154. The first insulating layer 140 may be referred to as a gate insulating layer. The first insulating layer 140 may not be located in the bending region BR.

[0074] A gate conductor including a scan line, a gate electrode 124 of a transistor TR, a first wire 127, and a second wire 129 is located on the first insulating layer 140. The gate conductor can be formed of the same material in the same process. The gate conductor can include a metal such as molybdenum (Mo), copper (Cu), aluminum (Al), silver (Ag), chromium (Cr), tantalum (Ta), titanium (Ti), or a metal alloy thereof. The first wire 127 can be connected to a display area DA (e.g., a signal line such as a data line or a driving voltage line) and a driver (e.g., a scan driver or a light emission driver), and the second wire 129 can be connected to an output pad of the integrated circuit chip 30 or a pad of the pad portion PP.

[0075] The second insulating layer 160 is located on the first insulating layer 140 and the gate conductor. The second insulating layer 160 may include an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride (SiON), and silicon oxyfluoride (SiOF). The second insulating layer 160 may be referred to as an interlayer insulating layer. The second insulating layer 160 may not be located in the bending region BR.

[0076] A data conductor including a data line, a driving voltage line 172, a source electrode 173 and a drain electrode 175 of a transistor TR, a voltage transmission line 177, and a connection wire 179 is located on the second insulating layer 160. The data conductor may be formed of the same material in the same process. The source electrode 173 and the drain electrode 175 may be connected to the source region and the drain region of the semiconductor layer 154, respectively, through contact holes formed in the second insulating layer 160 and the first insulating layer 140. The voltage transmission line 177 may transmit a power voltage such as a driving voltage, a common voltage, etc. Reference Figure 4 The alignment mark AM may be formed of the same material and in the same process as the source electrode 173 and the drain electrode 175. The alignment mark AM may be formed of the same material and in the same process as the gate electrode 124.

[0077] The connection wire 179 is mainly located in the bending region BR. The connection wire 179 may extend across the bending region BR in a direction substantially parallel to the second direction y. One end and the other end of the connection wire 179 are connected to the first wire 127 and the second wire 129 respectively through contact holes formed in the second insulating layer 160. Therefore, the first wire 127 and the second wire 129 as gate conductors are electrically connected to each other through the connection wire 179. Therefore, the signal output from the integrated circuit chip 30 (for example, a data signal, a control signal or a voltage signal), the signal input to the pad of the pad portion PP (for example, a driving voltage (ELVDD) or a common voltage (ELVSS)), etc. can be transmitted to the display area DA, the driving device, etc. through the second wire 129, the connection wire 179 and the first wire 127. Because the connection wire 179 bends when the bending region BR is bent, the connection wire 179 can be formed of a metal having excellent flexibility and a low Young's modulus. If the flexibility of the connection conductive line 179 is increased, since stress to strain is reduced, the risk of deterioration (eg, occurrence of cracks) or disconnection at the bending region BR may be reduced.

[0078] The data conductor may include metals such as aluminum (Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), molybdenum (Mo), tungsten (W), titanium (Ti), chromium (Cr), tantalum (Ta), and metal alloys thereof. The data conductor may be multi-layered and may have a three-layer structure, which includes, for example, a lower layer (auxiliary layer) for improving contact performance and an upper layer (capping layer) for preventing oxidation, etc. For example, the lower layer and the upper layer may include titanium (Ti), chromium (Cr), molybdenum (Mo), or tantalum (Ta). For example, the data conductor may be multi-layered, such as titanium / aluminum / titanium (Ti / Al / Ti), titanium / copper / titanium (Ti / Cu / Ti), or molybdenum / aluminum / titanium (Mo / Al / Ti), but the embodiment is not limited thereto.

[0079] The first protective layer 165 is located between the substrate 110 and the connecting wire 179 in the bending region BR. A portion of the first protective layer 165 may overlap the first insulating layer 140 or the second insulating layer 160. In the bending region BR, the first protective layer 165 may be directly located on the substrate 110, and the lower surface of the first protective layer 165 may contact the upper surface of the substrate 110. The first protective layer 165 may include an organic insulating material. The organic insulating material may include polyimide, an acryl-based polymer, a siloxane-based polymer, etc.

[0080] The gate electrode 124, the source electrode 173, and the drain electrode 175 form a transistor TR together with the semiconductor layer 154. In the illustrated transistor TR, the gate electrode 124 is located on the semiconductor layer 154, however the structure of the transistor TR is not limited thereto and may be variously modified.

[0081] The third insulating layer 180 is located on the second insulating layer 160 and the data conductor. The third insulating layer 180 is positioned in the bending region BR and near the bending region BR as the second protective layer 185 and forms the second protective layer 185. In the bending region BR, the second protective layer 185 may be located on the first protective layer 165. The third insulating layer 180 and the second protective layer 185 may be formed of the same material in the same process. The third insulating layer 180 and the second protective layer 185 may include organic insulating materials, for example, polyimide, acryl-based polymers, siloxane-based polymers, etc. The connecting wire 179 is sandwiched between the first protective layer 165 and the second protective layer 185. In other words, in the bending region BR, the connecting wire 179 is surrounded by the first protective layer 165 and the second protective layer 185 including organic insulating materials, thereby preventing it from being damaged when bending.

[0082] The pixel electrode PE is located on the third insulating layer 180 in the display area DA. The pixel electrode PE can be connected to the drain electrode 175 through a contact hole formed in the third insulating layer 180. The pattern IP is located on the second protective layer 185 in the bending area BR. The pattern IP can be formed of the same material in the same process as the pixel electrode PE. For example, a conductive material is deposited on the third insulating layer 180 and the second protective layer 185 by a sputtering method or the like to form a conductive layer, and then the conductive layer is patterned by a photolithography process to form the pixel electrode PE and the pattern IP together. If the pattern IP is formed by this method, there is no need to add a process for forming the pattern IP, and the pattern IP does not interfere with other conductors (i.e., the connecting wire 179) of the bending area BR.

[0083] The pattern IP may be formed together with other constituent elements in addition to the pixel electrode PE of the display area DA, or may be formed independently of constituent elements formed in the display area DA. The alignment mark AM may be formed of the same material in the same process as the pixel electrode PE.

[0084] The pixel electrode PE and the pattern IP may include a metal such as silver (Ag), nickel (Ni), gold (Au), platinum (Pt), aluminum (Al), copper (Cu), molybdenum / aluminum / neodymium (Mo / Al / Nd) or a metal alloy thereof. The pixel electrode PE and the pattern IP may include a transparent conductive material such as indium tin oxide (ITO) and indium zinc oxide (IZO). For example, the pixel electrode PE and the pattern IP may be a multilayer such as ITO / silver (Ag) / ITO.

[0085] The fourth insulating layer 360 having an opening overlapping the pixel electrode PE is located on the third insulating layer 180. The opening of the fourth insulating layer 360 may define each pixel region and is referred to as a pixel defining layer. The fourth insulating layer 360 may be located at the third protective layer 367 on the second protective layer 185 in the bending region BR. The fourth insulating layer 360 and the third protective layer 367 may be formed of the same material in the same process. The fourth insulating layer 360 and the third protective layer 367 may include an organic insulating material.

[0086] The emission layer EL is located on the pixel electrode PE. The common electrode CE that transmits the common voltage is located on the emission layer EL. The common electrode CE is formed by a thin laminated metal with a low work function, such as calcium (Ca), barium (Ba), magnesium (Mg), aluminum (Al), silver (Ag), etc., so as to have a light-transmitting property. The common electrode CE can be formed by a transparent conductive material such as ITO and IZO. The pixel electrode PE, the emission layer EL and the common electrode CE of each pixel constitute a light-emitting element such as an organic light-emitting diode OLED.

[0087] The encapsulation layer 390 is located on the common electrode CE. The encapsulation layer 390 can prevent moisture or oxygen from penetrating from the outside by encapsulating the organic light emitting diode OLED. The encapsulation layer 390 may be a thin film encapsulation layer in which an inorganic material layer and / or an organic material layer is deposited. In the exemplary embodiment shown, the encapsulation layer 390 is a thin film encapsulation layer including a first inorganic material layer 391, a second inorganic material layer 393, and an organic material layer 392 between the first inorganic material layer 391 and the second inorganic material layer 393. The encapsulation layer 390 may not be located in the bending region BR.

[0088] A polarizing layer for reducing reflection of external light may be positioned on the encapsulation layer 390. The polarizing layer may not overlap the bending region BR.

[0089] The bending protection layer 400 for relieving tensile stress and protecting the connection wire 179 is located on the third protection layer 367 in the bending region BR. The bending protection layer 400 may be referred to as a stress neutralization layer. The bending protection layer 400 may include an organic insulating material such as an acryl-based resin.

[0090] At least one dam D1 and D2 may be located between the encapsulation layer 390 and the bending region BR. The dams D1 and D2 may include a first dam D1 and a second dam D2. The first dam D1 may be located closer to the display area DA than the second dam D2, and the second dam D2 may be formed higher than the first dam D1. Each of the first dam D1 and the second dam D2 may include at least one layer. For example, the first dam D1 may include a first layer 365 and a second layer 405 located on the first layer 365. The first layer 365 may be formed of the same material in the same process as the fourth insulating layer 360, and the second layer 405 may be formed of the same material in the same process as the bending protection layer 400. The second dam D2 may include a first layer 186, a second layer 366, and a third layer 406. The first layer 186 may be formed of the same material in the same process as the third insulating layer 180, the second layer 366 may be formed of the same material in the same process as the fourth insulating layer 360, and the third layer 406 may be formed of the same material in the same process as the bending protection layer 400. The first dam D1 and the second dam D2 may have a function of preventing the organic material from overflowing toward the non-display area NA when the organic material layer 392 of the encapsulation layer 390 is formed. The first inorganic material layer 391 and the second inorganic material layer 393 configuring the encapsulation layer 390 may be formed to extend on the first dam D1 and the second dam D2. In this case, since the contact area of ​​the first inorganic material layer 391 and the second inorganic material layer 393 increases, the adhesion between the first inorganic material layer 391 and the second inorganic material layer 393 may increase.

[0091] The protective film 50 is located below the substrate 110. The protective film 50 may be attached to the substrate 110 by an adhesive such as a pressure-sensitive adhesive or an optically clear adhesive. As described above, the protective film 50 is removed in the bending region BR to reduce bending stress, and the adhesive present between the substrate 110 and the protective film 50 before removing the protective film 50 may remain at the lower surface of the substrate 110. The pattern IP formed in the bending region BR may be used to evaluate the remaining amount of the adhesive.

[0092] Figure 6 It is schematically shown Figure 1 A view of the cross-sectional structure of the bending region BR in FIG.

[0093] The bending region BR of the display panel 10 may have a structure in which the substrate 110, the first protective layer 165, the connecting wire 179, the second protective layer 185, the pattern IP, the third protective layer 367, and the bending protective layer 400 are sequentially deposited.

[0094] It is important to design the bending region BR so that the connecting wire 179 is not damaged during bending. To this end, the connecting wire 179 is located between the first protective layer 165 and the second protective layer 185 including an organic insulating material. In addition, the layers of the bending region BR may be formed so that the neutral plane of the bending region BR is positioned close to the connecting wire 179. The neutral plane is a surface within the bending region BR, at which the material of the bending region BR is not stressed (compressive stress or tensile stress) when the bending region BR is loaded by a bending force. During bending of the bending region BR, tensile stress is generated at a portion on (above) the neutral plane and compressive stress is generated at a portion below the neutral plane. Because the connecting wire 179 is more vulnerable to tensile stress than to compressive stress, the neutral plane may be slightly above the connecting wire 179, for example, on the second protective layer 185 as shown. Therefore, in order to locate the neutral plane, the bending protection layer 400 and the second and third protection layers 185 and 367 formed together with the third and fourth insulation layers 180 and 360 formed in the display area DA need to be formed thick.

[0095] Since the pattern IP is located above the connection wire 179, the pattern IP can move the neutral plane upward. In other words, the pattern IP controls the position of the neutral plane to be suitable for relieving the bending stress generated in the connection wire 179. In addition, by forming the pattern IP, even if the bending protection layer 400 for controlling the neutral plane is formed thinner, the neutral plane of the bending area BR can be controlled at a predetermined position. Figure 6 In the embodiment, the pattern IP is located between the second protection layer 185 and the third protection layer 367 , however, the pattern IP may be located between other layers, and may be located between the third protection layer 367 and the bent protection layer 400 .

[0096] Figure 7 yes Figure 1 Magnified view of the bending region in FIG. 1 and the area adjacent to the bending region.

[0097] refer to Figure 7 ,like Figure 4As shown in , the pattern IP may be formed to the bending region BR and the region adjacent to the bending region BR in the second direction y. In other words, in a plan view, the pattern IP may include a first virtual electrode Ed1 located above the bending region BR along the electrode E located in the bending region BR and a second virtual electrode Ed2 located below the bending region BR. As described above, if a pattern IP is formed that also includes the first virtual electrode Ed1 and the second virtual electrode Ed2, the neutral plane region of the bending region BR that can be controlled by the pattern IP can be extended to the region adjacent to the bending region BR, and a margin for the bending region BR can be obtained. In other words, even if the display panel 10 is not correctly bent in the intended bending region BR, and the region adjacent to the bending region BR is bent, because the neutral plane region is extended by the pattern IP, the wires (specifically, the connecting wires 179) located in the region can also be protected.

[0098] The pattern IP includes the first virtual electrode Ed1 of the first column and the second virtual electrode Ed2 of the first column, but may or may not include the first virtual electrode Ed1 of two or more columns and / or the second virtual electrode Ed2 of two or more columns. The pitch of the first virtual electrode Ed1 and the pitch of the second virtual electrode Ed2 may be the same as the pitch p of the electrode E. The shape and size of the first virtual electrode Ed1 and the second virtual electrode Ed2 may be the same as the shape and size of the electrode E, and may have various shapes, such as a quadrilateral, a polygon other than a quadrilateral, a circle, and an ellipse.

[0099] refer to Figures 8 to 12 Some exemplary embodiments of the pattern IP and the bending stress relief effects associated therewith are described.

[0100] Figure 8 and Fig. 9 is a view illustrating a pattern IP located at a bending region of a display device according to an exemplary embodiment.

[0101] refer to Figure 8 , the pattern IP includes a plurality of electrodes E and a bridge B connecting adjacent electrodes E. The width of the bridge B is smaller than the width of the electrode E, and may be, for example, about 5 μm to about 20 μm. The electrodes E may be quadrilaterals having the same size and may be arranged at the same interval s and pitch p. As described above, if Figure 4 In the embodiment of the present invention, the electrodes E of the pattern IP shown in FIG. 1 are connected by bridges B, the area density of the pattern IP in the bending region BR may be increased compared to the pattern IP including only the electrodes E. For example, the pattern IP may have an area density of about 20% to about 90% or about 40% to about 80%. If the area density of the pattern IP is increased, the bending stress control capability may be increased. On the other hand, when the pattern IP includes Figure 7When the first virtual electrode Ed1 and the second virtual electrode Ed2 are shown in FIG. , the first virtual electrode Ed1 and the second virtual electrode Ed2 can be formed by Figure 8 Connect to bridge B in the same manner as shown in FIG.

[0102] refer to Fig. 9 , showing an example in which each electrode E of the configuration pattern IP is circular. The electrode E may be circular with a diameter d of about 20 μm to about 100 μm, and a pitch p of the electrodes E may be about 30 μm to about 150 μm.

[0103] For example, when the pitch p of the electrodes E is set to about 70 μm, the electrodes E with a diameter d of about 50 μm can be arranged at an interval s of about 20 μm, and the electrodes E with a diameter d of about 35 μm can be arranged at an interval s of about 35 μm. The electrodes E are parallel to the first direction x and inclined to the second direction y, but the electrodes E can also be parallel to the second direction y.

[0104] Electrode E Figure 8 and Fig. 9 The electrodes E of various shapes may have a structure connected by bridges B.

[0105] Fig.10 and Fig.11 is a graph showing the influence on the connection conductive line 179 when the bending region is bent according to the shape of the pattern. Fig.12 is a graph showing the influence on the connection wire 179 when the bending region is bent according to the radius of curvature.

[0106] exist Fig.10 and Fig.11 In the figure, each of exemplary embodiments A to E is a case where the pattern IP is formed in the curved region BR, and exemplary embodiment F is a case where the pattern IP is not formed in the curved region BR. Each curved region BR is curved with a curvature radius of 1 mm.

[0107] Table 1

[0108]

[0109] refer to Fig.10 and Fig.11, as the area of ​​the electrode E increases under the same pitch p, strain and stress occur in large quantities and the strain and stress are the largest in the case of including the bridge B (exemplary embodiment E). This means that as the area density of the pattern IP increases, the effect of relieving bending stress is stronger. When the pattern IP is formed, the strain and stress appear to be greater than when the pattern IP is not formed. Therefore, the pattern IP can relieve the strain and stress during the bending of the bending region BR.

[0110] refer to Fig.12 When the bending region BR is bent, the curvature radius is approximately inversely proportional to the stress of the connecting wire 179. The pattern IP can more effectively alleviate the increase of the bending stress in the case of a smaller curvature radius.

[0111] So far, the bending of the bending area BR, the formation of the pattern IP, etc. have been described in the exemplary embodiment in the case where the display panel 10 is a front emission type. However, in the case where the display panel 10 is a bottom emission type, the bending direction of the bending area BR, the formation position of the pattern IP, etc. may be different from the above exemplary embodiment. In the case of mainly focusing on the differences from the above exemplary embodiment, reference is made to Fig.13 and Fig.14 A case where the display panel 10 is of a bottom emission type is described.

[0112] Fig.13 is a side view of the display device according to the exemplary embodiment after being bent, and Fig.14 is a cross-sectional view of a display device according to an exemplary embodiment.

[0113] refer to Fig.13 When the display panel 10 is a bottom emission type, the bending area BR may be Figure 3 Therefore, the pad portion PP and the flexible printed circuit film 20 may be bent to be located in front of the display panel 10. In this bending, in the bending region BR, a compressive stress is generated at an upper portion of the neutral plane, and a tensile stress is generated at a lower portion of the neutral plane.

[0114] refer to Fig.14 , showing that Figure 1 . Since the connection wire 179 is more vulnerable to tensile stress than to compressive stress, the neutral plane is suitably positioned slightly lower than the connection wire 179. Therefore, since the pattern IP can be formed below the connection wire 179 instead of above it to move the neutral plane downward, the bending stress of the connection wire 179 can be relieved.

[0115] In order to form the pattern IP without adding a process, before forming the connection wire 179, the pattern IP may be formed of the same material in the same process as the configuration (e.g., the gate electrode 124) formed in the display area DA. The pattern IP may be formed together with other constituent elements other than the gate electrode 124 of the display area DA, or may be formed independently of the constituent elements formed in the display area DA. In the case where the display panel 10 is a bottom emission type, since the light emitted from the emission layer EL of the organic light emitting diode OLED must be emitted to the rear surface of the display panel 10, the pixel electrode PE may be formed only of a transparent conductive material having a high work function or of a transparent conductive material layer and a semi-transmissive reflective metal layer.

[0116] Next, a description is given in conjunction with a processing accuracy check when the protective film is cut to remove the protective film in the bending region BR of the display panel 10. Descriptions of the constituent elements described above are omitted or simplified.

[0117] Fig.15 is a top plan view schematically illustrating a display device according to an exemplary embodiment. Fig.16 It is along Fig.15 A cross-sectional view taken along line XVI-XVI'. Fig.17 , Fig.18 , Fig.19 and Fig. 20 According to an exemplary embodiment, Fig.15 Magnified view of the area indicated by the single-dot dash line.

[0118] Fig.15 Shown as Figure 1 The display device shown in . Fig.16 Show Fig.15 1 and 10. The protective film 50 is attached to the rear surface of the display panel 10 except for the bending region BR. The protective film 50 includes a first portion 50a and a second portion 50b located at both sides of the bending region BR, respectively.

[0119] The pattern IP including the sub-pattern sIP is located in the bending region BR and near the bending region BR. In other words, the pattern IP is not limited to within the bending region BR but extends beyond the boundary of the bending region BR and is then disposed outside the bending region BR. Figures 1 to 14 The pattern IP for evaluating the residual adhesive R is described, and the pattern IP is used to evaluate the cutting accuracy of the protective film in the bending region BR. The display panel 10 may include both the pattern IP for evaluating the residual adhesive R and the pattern IP for evaluating the cutting accuracy of the protective film, or may include only one of them.

[0120] like Fig.16 As shown in FIG. 1 , the pattern IP may be located between the first protective layer 165 and the second protective layer 185. The pattern IP may be formed of the same material in the same process as the source electrode 173 and the drain electrode 175 of the transistor TR. In the curved region BR of the display panel 10, the connection wire 179 for transmitting data signals, control signals, driving voltages, etc. may be formed. Figure 5 , however, the connection wire 179 may be located in the edge portion of the right / left side of the bending region BR (for example, in an area within about 0.1 mm to 0.3 mm from the edge). Therefore, although the pattern IP is formed of the same data conductor as the source electrode 173, the drain electrode 175, and the connection wire 179, the pattern IP does not interfere with the connection wires that are other conductors of the bending region BR.

[0121] The pattern IP may be located between other layers. For example, the pattern IP may be located between the second protective layer 185 and the third protective layer 367, between the third protective layer 367 and the curved protective layer 400, between the buffer layer 120 and the first insulating layer 140, between the first insulating layer 140 and the second insulating layer 160, or between the substrate 110 and the first protective layer 165. The pattern IP may be formed of the same material in the same process as the semiconductor layer 154, the gate electrode 124, the pixel electrode PE, or the common electrode CE. As described above, if the pattern IP is formed together with the constituent elements formed in the display area DA, there is no need to add a process for forming the pattern IP.

[0122] In order to form the protective film 50 so as not to be located only in the bending region BR, the protective film 50 is completely attached to the rear surface of the display panel 10, the protective film 50 is laser cut at both sides of the bending region BR (both sides in the second direction y) along the first direction x, and the protective film portion located in the bending region BR is removed. The pattern IP is used to evaluate the degree of accuracy of laser cutting execution.

[0123] Fig.17 The state of cutting the protective film by laser at the upper and lower edges of the bending region BR is shown. After the protective film is cut but before the protective film portion 50' is removed, the protective film portion 50' is located in the bending region BR. The pattern IP includes electrodes E located at edge portions on both sides of the bending region BR at the right and left sides of the bending region BR. The pattern IP includes sub-patterns sIP at the upper and lower edge portions of the bending region BR near the edges on both sides of the bending region BR. The electrodes E configuring each sub-pattern sIP are located on the outside and inside of the bending region BR at the upper and lower edge portions of the bending region BR. Therefore, a portion of the sub-pattern sIP overlaps with the first portion 50a or the second portion 50b of the protective film 50.

[0124] An example is shown in which the pattern IP includes four sub-patterns sIP and the sub-pattern sIP is located inside the bending area BR compared to the alignment mark AM, however, the pattern IP may include less than four or more than four sub-patterns sIP, and the sub-pattern sIP may be located outside the bending area BR compared to the alignment mark AM.

[0125] By referring to the alignment mark AM, the CO 2 The laser cutting device of the laser cutter is aligned and irradiates a laser beam along the upper and lower edges of the bending area BR to perform laser cutting. If the laser beam is irradiated to the protective film, the protective film is melted by heat energy. If the protective film is cut by the laser beam, cuffs K1 and K2 having a predetermined width are generated due to volume loss. The protective film can be divided into protective films 50a and 50b that are not located in the bending area BR and a protective film portion 50' located in the bending area BR by the cuffs K1 and K2.

[0126] The cutting edges K1 and K2 are spaces where the protective film is removed by laser cutting. The cutting edges K1 and K2 limit the cut side surface of the protective film. The cutting edges K1 and K2 may have a cross-sectional shape of approximately a "U" character to a "V" character, and the maximum width may be about 100 μm to about 200 μm. Even if the irradiation position of the laser beam is aligned with reference to the alignment mark AM, an alignment error may occur due to equipment tolerance or material tolerance, so that the edge portion of the protective film facing the bending area BR may invade the bending area BR or move away from the bending area BR due to the alignment error. Therefore, if the laser cutting exceeds the allowable error level, after removing the protective film portion 50' located in the bending area BR or the portion other than the bendable portion of the bending area BR, excessive stress is generated at the bending area BR when bending, especially at the upper edge portion and / or the lower edge portion of the bending area BR. Therefore, cracks are generated in the wire located in or near the bending area BR, or the wire may be disconnected. Evaluating whether the laser cutting is performed correctly is to prevent the generation of defects and is required in the process.

[0127] As shown in the exemplary embodiment, since the pattern IP is formed at the upper edge portion and the lower edge portion of the bending region BR, the accuracy of laser cutting can be easily and correctly evaluated. In more detail, the sub-pattern sIP of the pattern IP may include electrodes E whose number increases as they are farther away from the upper edge of the bending region BR upward and downward, and the sub-pattern sIP may include electrodes E whose number increases as they are farther away from the lower edge of the bending region BR upward and downward. The electrodes E are formed symmetrically with respect to the upper edge of the bending region BR and are formed symmetrically with respect to the lower edge of the bending region BR. As described above, if the pattern IP is formed, the alignment level and processing accuracy of the laser cutting can be measured only by evaluating the number of electrodes E that do not overlap with the cutting edges K1 and K2 through visual inspection or the like.

[0128] For example, in Fig.17 At the upper edge of the bending region BR in FIG. 4 , seven electrodes E are above the cut edge K1 and nine electrodes E are below the cut edge K1. Because the electrodes E are symmetrically formed with respect to the upper edge of the bending region BR and the number of electrodes E below the cut edge K1 is greater than the number of electrodes E above the cut edge K1, it can be quickly confirmed that the cut edge K1 is slightly above the upper edge of the bending region BR. When inspected with an optical microscope, the electrodes E overlapping the cut edges K1 and K2 and the electrodes E not overlapping the cut edges K1 and K2 are different in brightness, for example, the overlapping electrodes E may appear darker, so it can be easily inspected. The sub-pattern sIP may have a structure in which the number of electrodes E decreases as they are farther away from the upper and lower edges of the bending region BR.

[0129] The size and spacing of the electrode E may be appropriately determined by considering the width of the cut edges K1 and K2 and the alignment margin accuracy. For example, the electrode E may be a square whose length l of one side is about 5 μm and may be formed with a spacing s1 of about 3 μm in the first direction x, a spacing s2 of about 5 μm in the second direction y, and a pitch p of 10 μm. The electrode E may be a square whose length l of one side is about 10 μm and may be formed with a spacing s1 of about 6 μm in the first direction x, a spacing s2 of about 10 μm in the second direction y, and a pitch p of 20 μm. As the pitch p of the electrode E decreases, the alignment error may be measured more accurately.

[0130] The shape and arrangement of the electrodes E can be varied in various ways. Fig.18 , Fig.19 and Fig. 20 , the electrodes E constituting the sub-pattern sIP may be arranged like an hourglass. Fig.19 As shown in , the electrode E may be circular, and may have other shapes. The electrode E may have a combination of several shapes. For example, Fig. 20As shown in , the electrode E may have a combination of a circular electrode E1 and a quadrilateral electrode E2. If the sub-pattern sIP includes electrodes E1 and E2 of different shapes in a regular manner, the alignment accuracy may be evaluated based on the shape and the number of electrodes E1 and E2 that do not overlap with the cut edges K1 and K2. Fig. 20 In the lower edge portion of the curved region BR, only the quadrilateral electrode E2 is arranged below the cut edge K2, and the circular electrode E1 and the quadrilateral electrode E2 are arranged above the cut edge K2. Therefore, it can be immediately grasped that the cut edge K2 is slightly below the lower edge of the curved region BR.

[0131] Quadrilateral and circular electrodes E are shown, however, the shape of the electrodes E is not limited if they are regularly arranged in a manner such that the number gradually increases or decreases as they move upward and downward away from the upper and lower edges of the bending region BR and can be identified by visual inspection, etc.

[0132] While the inventive concept has been described in conjunction with what are presently considered to be practical exemplary embodiments, it is to be understood that the inventive concept is not limited to the disclosed embodiments, but on the contrary is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. Display equipment, including: A display panel including a display area and a curved area, Wherein, the display panel in the curved area includes: Multiple connecting wires, A pattern comprising a plurality of electrodes, and a protective layer, located between the plurality of connecting wires and the pattern, wherein each electrode is insulated and not configured to transmit an electrical signal, and Wherein, the pattern is electrically insulated from the plurality of connecting wires.

2. The display device according to claim 1, wherein: The plurality of electrodes are arranged over at least 50% of the bending area.

3. The display device according to claim 2, wherein: Each of the electrodes is quadrilateral or circular.

4. The display device according to claim 2, wherein: The pattern also includes a plurality of bridges connecting the plurality of electrodes.

5. The display device according to claim 2, wherein: The display panel further includes a substrate, and The plurality of connection wires are positioned across the bending region on the substrate and are configured to transmit signals from outside the display panel.

6. The display device according to claim 5, wherein: The protection layer is located on the plurality of connection wires, and the pattern is located on the protection layer.

7. The display device according to claim 6, wherein: The display panel further includes a pixel electrode located in the display area, and The pattern is made of the same material as the pixel electrode.

8. The display device according to claim 5, wherein: The protection layer is located between the substrate and the plurality of connection wires, and the pattern is located between the substrate and the protection layer.

9. The display device according to claim 8, wherein: The display panel further includes a gate electrode located in the display area, and The pattern is made of the same material as the gate electrode.

10. The display device according to claim 1, wherein: The display panel further includes a first alignment mark and a second alignment mark respectively located at both sides of the bending area, and The pattern is located between the first alignment mark and the second alignment mark.

11. The display device according to claim 1, wherein: The pattern also includes a plurality of dummy electrodes adjacent to the bent region.

12. Display equipment, including: A display panel including a display area and a curved area; as well as a protective film positioned on one surface of the display panel so as not to overlap the bent area, in, The display panel includes a pattern including a plurality of electrodes arranged in the curved area, The protective film includes a first portion and a second portion respectively located at both sides of the bending area, and A portion of the pattern overlaps at least one of the first portion and the second portion.

13. The display device according to claim 12, wherein: The pattern includes a plurality of sub-patterns, and Each of the sub-patterns includes a plurality of electrodes symmetrically positioned with respect to one edge of the bending region.

14. The display device according to claim 13, wherein: Each of the sub-patterns includes a plurality of electrodes, and the number of the plurality of electrodes changes as being farther away from the edge of the bending region.

15. The display device according to claim 14, wherein: Each of the sub-patterns includes a plurality of electrodes, and the number of the plurality of electrodes increases as being farther away from the edge of the bending region.

16. The display device according to claim 13, wherein: Each of the electrodes is quadrilateral or circular.

17. The display device according to claim 13, wherein: Each of the sub-patterns includes a plurality of electrodes having two or more shapes.

18. The display device according to claim 12, wherein: The display panel further includes a substrate and a plurality of connecting wires on the substrate crossing the bending area, and The pattern is located at the same layer as the plurality of connection conductive lines.

19. The display device according to claim 18, wherein: In the bending area, the display panel further includes a first protection layer located between the substrate and the plurality of connection wires and a second protection layer located on the plurality of connection wires, and The pattern is located between the first protection layer and the second protection layer.

20. The display device according to claim 18, wherein: The display panel further includes a source electrode and a drain electrode located in the display area, and The pattern is made of the same material as the source electrode and the drain electrode.

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